This invention relates to a method of providing a fluid seal of the face-to-face surface type in a downhole drilling apparatus. One or more such seals may be used in connection with such an apparatus which necessarily requires a high degree of reliability and carefree operation in adverse operating conditions which makes remote the possibility of ready inspection and maintenance.
The fluid seal of the type provided with the apparatus and method herein described may be included as a part of a bearing assembly which is filled with lubricating fluid maintained at a higher pressure than the pressure externally acting upon the bearing assembly, thereby assuring that the lubricating fluid is not contaminated and that the entry of external fliuds and other foreign substances, such as drilling mud, is excluded.